irritant

1 of 2

noun

ir·​ri·​tant ˈir-ə-tənt 

: something that irritates or excites

irritant

2 of 2

adjective

: causing irritation

specifically : tending to produce physical irritation

Synonyms of irritant

Noun

• headache
• nuisance
• thorn
• frustration
• annoyance

Examples of irritant in a Sentence

Noun

dust and other lung irritants

The delay was a minor irritant.

Recent Examples on the Web

Noun

Fortunately, more and more brands are now formulating deodorants without common allergens and irritants. —Bestreviews, Chicago Tribune, 31 Mar. 2026

There certainly are harmful chemicals, carcinogens, toxins, heavy metals, respiratory irritants and other things inside of there that certainly can cause immediate harm. —Mary Kekatos, ABC News, 26 Mar. 2026

Adjective

No Kings protest ends March 38 with protesters detained and the use of a chemical irritant on some protesters. —Mark Russell, Memphis Commercial Appeal, 29 Mar. 2026

The fire department said Wednesday that the chemical released into the air was pepper spray, which is less concentrated than bear mace and creates a smaller irritant cloud. —Lucy Hodgman, San Francisco Chronicle, 11 Mar. 2026

Word History

First Known Use

Noun

1802, in the meaning defined above

Adjective

1636, in the meaning defined above

Kids Definition

irritant

1 of 2 adjective

ir·​ri·​tant ˈir-ə-tənt 

: tending to produce anger, annoyance, impatience, soreness, or inflammation

especially : tending to produce physical irritation

irritant

2 of 2 noun

: something that irritates

Medical Definition

irritant

1 of 2 adjective

ir·​ri·​tant ˈir-ə-tənt 

: causing irritation

specifically : tending to produce inflammation

irritant

2 of 2 noun

: something that irritates or excites

specifically : an agent by which irritation is produced

a chemical irritant